1. Field of Invention
The present invention relates to a notebook computer expansion base with a slidable cover structure, and more particularly to an expansion base suitable for notebook computers having different plug specifications by way of adjusting the distance between the slidable cover and an expansion slot through sliding the slidable cover.
2. Related Art
Referring to FIG. 1, it shows an expansion base of a conventional notebook computer. Generally, this type of expansion base includes an expansion portion 110 and a plug portion 120. The expansion portion 110 is used to accommodate at least one expansion unit 111, and the expansion unit 111 is an additionally disposed expansion component, such as a floppy drive, an optical disc drive, or a battery. The plug portion 120 is a portion for the expansion base to be plugged into the notebook computer, and it generally has a plug slot 121 electrically connected with the expansion unit 111, so as to form an electrical connection between the notebook computer and the expansion unit 111. Furthermore, a fixed plug gap 122 is reserved between the space between the plug portion 120 and the expansion portion 110 and the plug slot 121 for the notebook computer to be configured for plugging. In addition, in order to fix the expansion base on the notebook computer more firmly, a positioning element 123 and a buckling element 124 corresponding to each other are respectively disposed on the plug portion 120 and the notebook computer, such that the expansion base is firmly plugged to the notebook computer.
However, this method has an unavoidable defect, that is, the length of the fixed plug gap is definitely a fixed value, and thus, after being designed and formed, the expansion base only can be disposed on the notebook computer with a specific plug specification. If it is used to the notebook computer with a different plug specification, the expansion base cannot be mounted due to an insufficient fixed plug gap, or even through the expansion portion is mounted on the notebook computer, the expansion portion and the notebook computer do not press against each other and a redundant space is formed due to an excessive large length of the fixed plug gap, and thus, the expansion base tends to shake or fall off due to the unstable center of gravity and being crashed by an external force. Moreover, the positioning structure, the buckling structure, and the plug slot are easy to be damaged.